Same card, similar problem.

What OS and driverset are you using?

Mine is an ASUS 7700 Deluxe, GeForce2 GTS (el grande denario). After using it for a while, and being annoyed to death with the artifacts (I am in graphic design), I uninstalled the ASUS drivers that give access to the TV IN/Out features and set it up using just the default Detonator drivers from Nvidia. This helped, although did not reduce, the number of artifacts. These artifacts were visible on the Windows 98 statup screen and also visible on the desktop and inside applications.

I further made sure the thing was not overclocked, and I bought and installed a slot cooler for the card. I reseated the card, no avail. No help from Nvidia or ASUS.

However, I recently upgraded to Win2000, clean install, using the latest, greatest Detonator from Nvidia. I haven't seen any artifacts yet.